Headphone



FIG. 1 is a perspective view of a headphone showing the new design;

FIG. 2 is a another perspective view thereof;

FIG. 3 is an front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a side elevational view thereof; and,

FIG. 6 is an bottom view thereof.

The broken lines form no part of the claimed design. 

CLAIM The ornamental design for a headphone, as shown and described. 